Groundwater quality assessments of phreatic and deeper aquifers of the eastern Palghat, Kerala, Southern India

Identification and management of groundwater quality is crucial for maintaining the resources of over-exploited areas in the rain shadow region of the hard rock aquifer, which is essential for sustainable development. This research aims to identify water quality analysis for drinking and agricultural harvest in the crystalline aquifer, located in the eastern Palghat, Kerala, southern India. A groundwater compatibility study was conducted by analysing in situ parameters, major cations, anions, macronutrients, and fluorine in groundwater. Irrigational water quality parameters like Soluble Sodium Percentage (SSP), Sodium Adsorption Ratio (SAR), and Kelly's Ratio (KR), Permeability Index (PI) and Magnesium Hazard were obtained from 48 samples, 24 from excavated wells and 24 from tube wells (TW) in the exact location. The Water Quality Index (WQI) and irrigation water quality (IWQ) index are utilised due to their high importance in identifying the quality of water resources for irrigation and drinking purposes. Groundwater is the essential source for domestic, agricultural, and industrial purposes in the eastern Palghat, Kerala, southern India. This paper presents geochemical analyses of groundwater collected from phreatic and deeper aquifers of the area. Groundwater quality analyses show a considerable difference in the groundwater chemistry of phreatic and deeper aquifers. Excess fluoride is noted in a few samples. Rainwater harvesting, nanotechnology-based filters and awareness programs are recommended for reliable groundwater management in the study area. • Excess fluoride concentration in groundwater, where about 29 % of deeper aquifers and 14% of phreatic aquifers. • Groundwater in the study area is suitable for drinking and irrigation purposes, except for some isolated patches. • To enhance groundwater quality, the implementation of managed aquifer recharge structures in appropriate sites is crucial.